Spheroidal resid hydrodemetallation catalyst

ABSTRACT

Spheroidal catalyst support, supported catalyst, and method of preparing and using the catalyst for hydrodemetallation of metal-containing heavy oil feedstocks are disclosed. The catalyst supports comprise titania alumina having 5 wt % or less titania and have greater than 30% percent of their pore volume in pores having a diameter of between 200 and 500 Å. Catalysts prepared from the supports contain Group 6, 9 and 10 metals or metal compounds supported on the titania alumina supports. Catalysts in accordance with the invention exhibit improved catalytic activity and stability to remove metals from heavy feedstocks during a hydrotreating process. The catalysts also provide increased sulfur and MCR conversion during a hydrotreating process.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/378,894, filed Aug. 14, 2014, which is a national phaseentry under 35 U.S.C. § 371 of International Application No.PCT/US2013/026323 filed Feb. 15, 2013, published in English, whichclaims priority from U.S. Provisional Patent Application No. 61/600,024filed Feb. 17, 2012, all of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to the catalytic hydrotreating of liquidhydrocarbon containing feed streams. In particular, the presentinvention relates to a catalyst carrier, catalyst compositions preparedusing the carrier, a method of preparing the catalyst compositions and aprocess of reducing the metals content of a hydrocarbon heavy feedstockusing the aforementioned catalyst compositions.

BACKGROUND OF THE INVENTION

In the petroleum refining industry it is often useful to upgrade certainoil and fractions like heavy oils and residuum by hydrotreating.Examples of such hydrotreating processes are hydrodemetallation,desulfurization, and denitrogenation. In these processes the feedstockis contacted with a hydroconversion catalyst in the presence of hydrogenat elevated pressure and temperature. Due to strict demands imposed byecological regulations, the refining industry has become increasinglymore focused on producing high quality cleaner fuels with a minimumcontent of contaminants such as sulfur, nitrogen and heavy metals.

Catalysts used in hydrotreating processes generally comprisecatalytically active metals from Groups 6, 9 and 10 of The PeriodicTable and are typically supported on alumina, which may be combined withother inorganic refractory materials such as silica, magnesia, titania,zirconia and the like. Secondary promoters or additives, such ashalogens, phosphorous and boron, have also been used to enhancecatalytic properties. To achieve the maximum effect from hydrotreatingprocesses, it is necessary to optimize catalyst activity and selectivityto a desired hydrotreating reaction. Catalyst activity and selectivityare determined and affected by such factors as the nature and propertiesof the catalyst support, the catalytic agents, activity and selectivityof promoters as well as the preparation and activation method used.

Where heavy feedstocks contain organometallic compounds, theeffectiveness of the hydrotreating as well as downstream catalysts tendto decline relatively rapidly, particularly when the impurity is morethan about 10 to 20 ppm metals such as dissolved nickel and vanadium.These metallic impurities are said to deposit on the surface and in thepores of these catalysts reducing their effectiveness. One approach tothe problem of metal impurity has been to alter the pore structure ofthe hydrotreating catalyst. However, the determination as to which porestructure to use is unpredictable and not easily obtained. There is yeta conflict in the art regarding optimal pore structure. Several patentswhich have discussed this conflict include U.S. Pat. Nos. 4,066,574;4,113,661 and 4,341,625.

Hydrotreated hydrocarbon feedstocks having a low Conradson carbonresidue are also highly desirable in the refining industry. Carbonresidue is a measurement of the tendency of a hydrocarbon to form coke.Expressed in weight percent, carbon residue may be measured asmicrocarbon residue (MCR). The MCR content in a hydrotreated residualfeedstock is an important parameter since the hydrotreated residueusually acts as feed to a coker or a fluid catalytic cracking (FCC)unit. Decreasing the MCR content in the hydrotreated residue decreasesthe amount of low value coke generated in the coker and increases theamount of gasoline generated in the FCC unit.

To this end, there remains a need to develop catalyst compositions thatare less expensive and/or more effective in removing metal contaminantsfrom hydrocarbons feed streams, in particularly heavy hydrocarbon feedstreams, than catalysts presently employed. There also remains a needfor improved hydrodemetallation and/or hydrodesulfurization catalystswhich provide good MCR conversion during a hydrotreating process.

SUMMARY OF THE INVENTION

The present invention is based on the discovery that the hightemperature calcination of a titania alumina material containing 5 wt %or less titania (based on the total weight of titania alumina)unexpectedly provide spheroidal catalyst supports having a unique porestructure from which supported catalysts having increased catalyticactivity and stability to remove metals during a hydrotreating processmay be prepared. Advantageously, the supports of the invention offer theeconomical benefit of lower cost since catalyst compositions preparedfrom the supports have improved catalytic performance while maintaininga low catalytically active metal content.

In one aspect of the present invention, a spheroidal titania aluminasupport having a distinct pore structure is provided. The support of theinvention has a pore size distribution as determined by mercurypenetration porosimetry satisfying the following: a total pore volume inthe range of from about 0.7 to about 1.2 cc/g, with greater than 40% ofthe total pore volume having pores in a diameter larger than 200 Å,about 30% or more of the total pore volume having pores in the range ofabout 200 Å to about 500 Å and, greater than 10% of the total porevolume having pores with a diameter above 1000 Å.

The present invention also provides a spheroidal titania alumina supportwhich comprises at least 90 wt % of a titania alumina having an aluminaR value of from about 0.4 to about 1.7, the R value being defined as theratio between the integrated intensity of the X-ray diffraction peak at2θ=32° and the integrated intensity of the X-ray diffraction peak at2θ=46°.

In another aspect of the present invention improved hydrotreatingcatalysts for reducing the content of metals of a heavy hydrocarbon feedstock containing metals during a hydrotreating process are provided. Inaccordance with the invention the catalyst are prepared by impregnatingcatalytically active Group 6, 9 and 10 metals or metal compounds, andoptionally phosphorous compounds, on a support in accordance with theinvention.

The present invention also provides improved hydrotreating catalystswhich have the ability to reduce the content of metals simultaneouslywith reducing the content of sulfur and the MCR of a heavy hydrocarbonduring a hydrotreating process.

Yet another aspect of this invention provides a method of makingspheroidal titania alumina supports having a distinctive pore sizedistribution using a gelation oil-drop process in a dripping column.

Another aspect of the present invention provides a method of making aspheroidal catalyst composition comprising a spheroidal titania aluminasupport, which support comprises at least 90 wt % titania alumina havingan R value of from about 0.4 to about 1.7 and containing 5 wt % or lesstitania, based on the total weight of titania alumina.

The present invention further provides improved hydrotreating processesusing spheroidal supported catalyst compositions and processes of thepresent invention.

These and other aspects and embodiments of the present invention aredescribed in further details below.

DETAILED DESCRIPTION OF OF THE INVENTION

The present invention provide spheroidal catalyst compositions comprisedof catalytically active metals or metal compounds of Groups 6, 9 and 10of The Periodic Table, and optionally, phosphorous compounds supportedon a spheroidal titania alumina support in accordance with theinvention. In one embodiment of the invention, the support material usedto prepare the catalyst of the invention generally comprises a titaniaalumina which contains 5 wt % or less titania, based on the total weightof the titania alumina. In another embodiment of the invention thetitania alumina comprises from about 2.5 to about 4 wt % titania, basedon the total weight of the titania alumina. In yet another embodiment ofthe invention, the titania alumina comprises from about 0.3 to about 1wt % titania.

In a preferred embodiment of the invention, the titania alumina used toprepare the supports of the invention comprises at least 90 wt. % of analumina having a mixture of gamma-alumina and delta- and/ortheta-alumina, such that the titania alumina composition is reflected byan alumina R value in the range of from about 0.4 to about 1.7,preferably from about 0.6 to about 1.4. The term “R value” as usedherein is used to indicate the ratio between the integrated intensity ofthe X-ray diffraction peak at 2 θ=32° and the integrated intensity ofthe X-ray diffraction peak at 2 θ=46°. R values are determined by amethod as disclosed and described in U.S. Pat. No. 5,888,380, the entirecontents of which is herein incorporated by reference.

The R value can be expressed in by the formula:

$R = \frac{\left\lbrack {{I\left( {2\theta} \right)} = {32{^\circ}}} \right\rbrack}{\left\lbrack {{I\left( {2\theta} \right)} = {46{^\circ}}} \right\rbrack}$in which [I(2θ)=32°] and [I(2θ)=46°] stand for the integrated intensityof the peak at a 2θ angle of the X-ray diffraction spectrum at 32° and46°, and 46°, respectively. In the present specification, use is made ofa PANalytical X'Pert X-RAY DIFFRACTOMETER. The following measurementconditions and apparatus were used: CuK alpha-ray vessel, vessel voltage50 kV, vessel current 30 mA, double axis vertical goniometer, scanningrate 0.867°/min, emitting slit width 1°, scattering slit width, 1°,receiving slit width 0.3 mm, 2θ angle 4°≤2θ≤82°. The peak which appearsat 2θ=46° is due to gamma-alumina, while the peak appearing at 2θ=32° isdue to delta- and/or theta-alumina. At this angle the latter two aluminatypes cannot be distinguished from each other by way of X-raydiffraction. The two peaks at 2θ=46° and 2θ=32° do not overlap and cantherefore be readily integrated to calculate the integrated intensity.In calculating the integrated intensity, the background intensity is nottaken into account, as is well known to the person skilled in the art.

In this respect it is noted that the R value should be determined on asupport, on which no catalytically active metals are present.

The spheroidal titania alumina supports in accordance with the presentinvention generally comprise at least 90 wt % of titania alumina asdescribed herein. Preferably, the support material comprises at least 95wt %, most preferably, greater than 99 wt % of the titania alumina, saidweight percent being based on the total weight percent of the support.The support material thus can “consist essentially of” the titaniaalumina as described herein. The phrase “consist essentially of” as usedherein with regard to the composition of the support material is usedherein to indicate that the support material may contain the titaniaalumina and other components, provided that such other components do notmaterially affect or influence the catalytic properties of the finalhydroconversion composition.

Spheroidal titania alumina supports of the present invention possessspecific properties of surface area, pore volume and pore volumedistribution. Unless otherwise specified herein, the pore volume andpore size distribution properties of the titania alumina supports asdefined herein are determined by mercury penetration porosimetry. Themercury measurement of the pore volume and the pore size distribution ofthe alumina support material is performed using any suitable mercuryporosimeter capable of a pressure range of atmospheric pressure to about4,000 bar, with a contact angle, θ=140° and with a mercury surfacetension of 0.47 N/m at room temperature.

Surface area as defined herein is determined by BET surface areaanalysis. The BET method of measuring surface area is described indetail in an article by Brunauer, Emmett and Teller in J. Am. Chem. Soc.60 (1938) 309-319, which article is incorporated herein by reference.

The surface area of the titania alumina support ranges from about 80m²/g to about 150 m²/g. In a preferred embodiment of the invention, thesurface area of the titania supports ranges from about 90 m²/g to about130 m²/g.

Generally, supports of the invention have a total pore volume in therange of from about 0.6 cc/g to about 1.2 cc/g. In a preferredembodiment of the invention, the total pore volume of the supportsranges from about 0.8 to about 1.1 cc/g.

The support of the invention has a distinct pore volume distributionsuch that generally greater than 40% of the total pore volume have poresin a diameter larger than 200 Å, with about 30% or greater of the totalpore volume having pores in a diameter in the range of about 200 Å toabout 500 Å and, greater than 10% of the total pore volume having poreswith a diameter above 1000 Å.

In one embodiment of the invention, about 50% to about 90% of the totalpore volume of the supports has pores in a diameter larger than 200 Å.

In another embodiment of the invention, about 30% to about 80% of thetotal pore volume of the supports has pores with a diameter ranging fromabout 200 Å to about 500 Å.

In yet another embodiment of the invention, greater than about 15% ofthe total pore volume has pores with a diameter above 1000 Å.

Spheroidal titania alumina supports of the invention have a generalspherical or oblate shape and may be in the form of pellets, extrudates,and the like. The supports of the invention may be prepared by anyconventional method in the catalyst arts useful for making a spheroidalshaped support, provided however that the final support have the desiredpore structure. Generally, supports of the invention are prepared by aprocess comprising co-precipitating a titania alumina containing 5 wt %or less titania under specific and controlled conditions of reactiontemperature, time, and pH. In a preferred embodiment of this invention,the titania alumina spheroidal support is prepared by an externalgelation oil-drop process as disclosed and described in U.S. Pat. No.4,270,779, said reference incorporated herein in its entirety byreference. In the titania-alumina co-precipitation process, a sufficientamount of an aqueous aluminum sulfate and titanium sulfate mixture isadded simultaneously with sodium aluminate to a water heel at atemperature of about 50° C. to about 80° C. to precipitatetitania-alumina having 5 wt % or less titania in the co-precipitatedtitania-alumina. During the precipitation step, the pH of the slurry ismaintained at about 7.2 to about 9.0 and the temperature is maintainedfrom about 50° C. to about 80° C. At the end of the precipitation step,the pH of the slurry is adjusted to about 8.6 to about 9.3 to enablemaximum removal of residual impurities, e.g. soda and sulfates.Thereafter, the co-precipitated titania alumina is filtered, washed withwater and dried to provide a titania alumina having a moisture contentfrom about 22 wt % to about 40 wt %, preferably from about 25 wt % toabout 32 wt %, as determined by a moisture analyzer at 955° C.

The dried titania alumina is thereafter peptized by mixing with asuitable peptizing agent to form an aqueous acidic titania aluminaslurry containing from about 20% to about 35, preferably from about 22%to about 30% solids. Droplets of the slurry are thereafter passedthrough air into a suitable dripping column containing an upper body ofa water immiscible liquid, e.g. kerosene, toluene, heavy naptha, lightgas oil, paraffin oil and the like, and anhydrous ammonia and a lowerbody of aqueous alkaline coagulating agent, e.g. ammonium hydroxidesolution, to form spheroidal particles. The titania alumina spheroidsare dried to a total moisture content of about 20 wt % to 35 wt % andare thereafter calcined at a high temperature ranging from about 960° C.to 1100° C., preferably from about 980° C. to about 1060° C., for about1 hour to about 3 hours, to obtain a final titania alumina spheroidalsupport having the desired pore structure.

Optionally, the titania alumina slurry is aged with agitation prior toformation of the droplet in the dripping column. Agitation and aging ofthe slurry aid in forming a uniform material with a viscosity thatpermits proper formation of droplets from which the spheroids can beformed. For droplet formation, slurry viscosities of about 300 to about2000 cps, preferably about 600 to about 1500 cps are suitable. Agitationof the slurry may be accomplished by a variety of means ranging fromhand stirring to mechanical high shear mixing. Following agitation, theslurry is aged from a few minutes to many days. Preferably, the slurryis aged for about 1 hr to about 3 hrs.

The length of the column can vary widely and will usually range fromabout 10 to about 30 feet in height. The organic phase may generallycomprise from about 30% to about 60% of the column length and thecoagulation phase the remainder. As will be understood by the oneskilled in the arts, the cross sectional area of the dripping columnwill vary depending upon the number of droplet nozzles used. Typically,the cross sectional area of the column ranges from about 50 inch squaredto about 500 inch squared.

Suitable peptizing agents useful to prepare the supports of theinvention include, but are not limited to, nitric acid, acetic acid,hydrochloric acid and other strong monobasic acids. In a preferredembodiment of the invention, the peptizing agent is a mixture of nitricacid and acetic acid.

Spheroidal supports in accordance with the invention may have varioussizes. Generally the support has an average particle size ranging fromabout 0.5 mm to about 15 mm. In a preferred embodiment of the invention,the spheroid support has a diameter ranging from about 1 to about 10 mm.In a more preferred embodiment the diameter ranges from 2 to about 5 mm.As will be understood by one skilled in the catalyst arts, catalystparticles produced from the supports will have a similar size and shapeas the support.

Catalysts in accordance with the invention are prepared by contactingtitania alumina supports of the invention with an aqueous solution of atleast one catalytically active metal or precursor compound to uniformlydistribute the desired metal on the support. Preferably, the metal isdistributed uniformly throughout the pores of the support. In oneembodiment of the invention, the catalysts are prepared by impregnationof the catalyst supports to incipient wetness with an aqueous solutionof the desired catalytically active metal or precursor metal compound.

Catalytically active metal and/or precursor metals compounds useful toprepare the catalyst composition of the invention, include, but are notlimited to metals or compounds of metals selected from the groupconsisting of Group 6 of The Periodic Table, Group 9 of The PeriodicTable, Group 10 of The Periodic Table and combinations thereof.Preferred Group 6 metals include, but are not limited to, molybdenum andtungsten. Preferred Groups 9 and 10 metals include, but are not limitedto, cobalt and nickel.

Concentrations of Group 6 metals and/or metal compounds useful toprepared catalyst composition of the present invention typically is anamount sufficient to provide from about 1 wt % to about 10 wt % of thedesired Group 6 metal, preferably from about 2 wt % to about 5 wt %, inthe total catalyst composition. Concentrations of Group 9 metals and/ormetal compounds useful to prepare the catalyst compositions of thepresent invention typically is an amount sufficient to provide fromabout 0 wt % to about 5 wt % of the desired Group 9 metal, preferablyfrom about 0.5 wt % to about 2 wt %, in the total catalyst composition.Concentrations of Group 10 metals and/or metal compounds useful toprepare the catalyst compositions of the present invention typically isan amount sufficient to provide from about 0 wt % to about 5 wt % of thedesired Group 10 metal, preferably from about 0.5 wt % to about 2 wt %,in the total catalyst composition.

In a preferred embodiment of the invention the catalytic agent is acombination of nickel and molybdenum. In a more preferred embodiment ofthe invention, the resulting catalyst comprises Mo concentrations in therange of about 2 wt % to about 4 wt % and Ni concentrations in the rangeof about 0.5 wt % to about 2 wt %, said percentages being based on thetotal catalyst composition.

Suitable metal compounds of Groups 9 and 10 metals include, but are notlimited to, metallic salts such as nitrates, acetates and the like.Suitable metal compounds of Group 6 metals include, but are not limitedto, ammonium molybdate, molybdic acid, molybdenum trioxide, and thelike.

Catalytically active metals contemplated for use in the presentinvention are preferably used in the form of oxides and/or sulfides ofthe metals. In the more preferred embodiment of the invention, thecatalytically active metals are used in the form of oxides.

Catalyst compositions of the invention may also comprise a phosphoruscomponent. In this case, the impregnating solution may also contain aphosphorus compound, such as for example phosphoric acid, phosphates,and the like, in addition to desired catalytically active metal or metalcompounds. Concentrations in the range of about 0 to about 2 wt %phosphorous, based on the total weight of the catalyst composition, aresuitable for use in catalysts of the invention.

Following treatment with the desired catalytic agent/s, the catalystsare optionally dried at a temperature in the range of from about 100° C.to 200° C. for about 10 minutes to about 2 hours, and thereafter theresulting catalysts are calcined at a temperature in the range of fromabout 300° C. to about 600° C. for about 1 hour to about 3 hours, toconvert at least part, preferably all, of the metal components orprecursors to the oxide form.

As will be clear to a person skilled in the art, there is a wide rangeof variations on the impregnating method used to support the catalyticactive metals on the supports. It is possible to apply a plurality ofimpregnating steps or the impregnating solutions may contain one or moreof the metal components or precursors to be deposited, or a portionthereof. Instead of impregnating techniques, dipping methods, sprayingmethods and the like can be used. In the case of multiple impregnations,dipping, and the like, drying and/or calcining may be carried out asbetween steps.

The catalysts of the invention exhibit an increased catalytic activityand stability for hydrodemetallization of a heavy hydrocarbon feedstockcontaining metals during a hydrotreating process. The heavy hydrocarbonfeedstock useful in the present invention can be obtained from anysuitable source of hydrocarbons, including, for example, petroleum crudeoils and tar sand hydrocarbons, such as, the heavy oils extracted fromtar sand. The heavy hydrocarbon feedstock can be a vacuum resid oratmospheric resid component of a petroleum crude oil or a tar sandhydrocarbon. The heavy hydrocarbon feedstock may also include light andheavy gas oils, as well as petroleum crude oil, atmospheric residues andvacuum residues blended with gas oils, particularly vacuum gas oils,crudes, shale oils, and tar sand oils.

The heavy hydrocarbon feedstock generally will include a mixture ofhydrocarbons derived from a crude oil or tar sand hydrocarbon materialor other source of heavy hydrocarbons. A portion, preferably a majorportion, of the heavy hydrocarbons of the mixture has a boilingtemperature exceeding about 343° C. (650° F.). The heavy hydrocarbonfeedstock is thus defined as having a boiling range, as determined byASTM test procedure D-1160, such that at least about 20 wt % of theheavy hydrocarbon feedstock boils at a temperature exceeding 524° C.(975° F.). The preferred heavy hydrocarbon feedstock has a boiling rangesuch that at least 30 wt % boils at a temperature exceeding 524° C.(975° F.), and, most preferably, at least 40 wt % of the heavyhydrocarbon feedstock boils at a temperature exceeding 524° C. (975°F.).

The API gravity of the heavy hydrocarbon feedstock can range from about3 to about 20, but, more specifically, the API gravity is in the rangeof from 4 to 15, and, more specifically, from 4 to 11.

The heavy hydrocarbon feedstock can have a Conradson carbon residuecontent, as determined by ASTM testing method D-189, exceeding 5 weightpercent and, more specifically, the Conradson carbon residue content isin the range of from 8 weight percent to 30 weight percent.

As earlier noted, the metals contained in the heavy hydrocarbonfeedstock can include nickel or vanadium, or both. The nickelconcentration in the heavy hydrocarbon feedstock can exceed 10 parts permillion by weight (ppmw) or it can exceed 30 ppmw. More specifically,the nickel concentration in the heavy hydrocarbon feedstock can be inthe range of from 40 ppmw to 500 ppmw. The vanadium concentration in theheavy hydrocarbon feedstock can exceed 50 ppmw or it can exceed 100ppmw. More specifically, the vanadium concentration in the heavyhydrocarbon feedstock can be in the range of from 150 ppmw to 1500 ppmw.

Catalysts of the invention are also useful to increase thehydrodesulfurization activity simultaneously with hydrodemetallizationduring a hydrotreating process where the hydrocarbon feedstock containsboth sulfur and metals. The sulfur content of the feed is generallyabove 0.1 wt % and will frequently be more than 1 wt %.

Further, catalysts in accordance with the present invention provide anincreased micro carbon residue (MCR) conversion during a hydrotreatingprocess as compared to prior demetallation and/or desulfurizationcatalysts prepared from alumina or aluminia titania supports where thesupports are calcined at a low temperature (i.e. below 960° C.).Consequently, the hydrotreated hydrocarbon fraction obtained exhibits areduced MCR content as compared to the MCR content of the starting heavyhydrocarbon feedstock.

A hydrotreating process employing the catalyst compositions of thisinvention may be carried out under hydrotreating process conditions inan apparatus whereby an intimate contact of the catalyst compositionwith said metal containing feedstock and a free hydrogen containing gasis achieved, to produce a hydrocarbon-containing product having areduced level of metals, e.g., nickel and vanadium, and, optionallysulfur. In accordance with the invention, the hydrotreating process ispreferably carried out using an Onstream Catalyst Replacement (OCR)technology. Typical hydrotreating process conditions useful in theinvention include, but are not limited to, reaction temperatures rangingfrom about 300° to about 450° C., hydrogen pressures of about 25 toabout 200 bar, H₂:oil ratios ranging from about 150 to about 1500 N1/1,and space velocities (hr-¹) of about 0.1 to about 5. In one embodimentof the invention, the operating conditions for metal containinghydrocarbon feedstock desulfurizaton process include a reaction zonetemperature of about 370° C. to about 400° C.′ a pressure of about 100to about 200 bar, and a hydrogen feed rate between about 200 and about500 N1/1 of oil feed.

To further illustrate the present invention and the advantages thereof,the following specific examples are given. The examples are given asspecific illustrations of the claimed invention. It should beunderstood, however, that the invention is not limited to the specificdetails set forth in the Examples.

All parts and percentages in the examples as well as the remainder ofthe specification that refers to solid compositions or concentrationsare by weight unless otherwise specified. However, all parts andpercentages in the examples as well as the remainder of thespecification referring to gas compositions are molar or by volumeunless otherwise specified.

Further, any range of numbers recited in the specification or claims,such as that representing a particular set of properties, units ofmeasure, conditions, physical states or percentages, is intended toliterally incorporate expressly herein by reference or otherwise, anynumber falling within such range, including any subset of numbers withinany range so recited.

EXAMPLES

Five catalysts (A, B, C, D and E) were prepared and their performanceevaluated. R values were determined as described hereinabove.

Example 1

Alumina was prepared by co-precipitation by runoff of aqueous streams ofaluminum sulfate and sodium aluminate followed by filtration/washing anddrying step. The dried powder contains 100% wt % Al₂O (dry basis). Thepowder contained 32% water.

The alumina powder was peptized by mixing nitric acid/acetic acid andwater to form a slurry containing 25% solids. The slurry was formed intospheres on the dripping column. Wet spheres were dried at 120° C. andcalcined at 1080° C. for 1 hour in a muffle to give calcined sphereshaving a R value of 0.47.

The calcined spheres were impregnated with Mo—Ni—P aqueous impregnationsolution by incipient wetness technique and then dried and calcined at510° C. to decompose the Mo—Ni—P impregnation solution compounds. Thefinished catalyst, identified as Catalyst A, had a nominal active metalcontent of 3 wt % Mo, 1 wt % Ni, 1 wt % P. Catalyst properties were asidentified in Table 1 below.

Example 2

Aqueous streams of aluminum sulfate (7% Al₂O₃) and titanium sulfate (9%TiO₂) were mixed in a 9:1 ratio to form an aluminum-titanium sulfatemixture. Water (165 gallons) was added to the strike tank and heated to57° C. and the contents of the strike tank were maintained at thistemperature for the remainder of the process. Five gallons ofaluminum-titanium sulfate mixture was added to the strike tank prior toprecipitation process. After that the aluminum sulfate and titaniumsulfate mixture and sodium aluminate were concomitantly added to thestrike tank. The aluminum sulfate and sodium sulfate mixture were addedat constant flow and the sodium aluminate flow rate was varied tomaintain a constant pH of 8.4 in the strike tank. The aluminum-titaniumsulfate mixture flow was stopped 50 minutes after the start of thesimultaneous aluminum-titanium sulfate mixture and sodium aluminateflows. At this time the concentration of precipitated titania-aluminasolids was about 6 wt %. The sodium aluminate flow was reduced to 0.7gallons per minute and turned off when a pH of 9.2 was obtained in thestrike tank. The precipitated titania alumina mix was then filtered andwashed on a filter belt to remove residual sodium sulfate. The resultingfilter cake was then spray dried. Dried titania alumina powder was thenused to make a catalyst support.

The dried titania alumina powder contains 3.5 wt. % TiO₂ (dry basis) andthe balance (dry basis) is alumina (Al₂O₃). The powder contained 26%water. The titania-alumina powder was peptized by mixing nitricacid/acetic acid and water to form a slurry containing 24% solids. Theslurry was formed into spheres on a dripping column. Wet spheres weredried at 120° C. and calcined at a temperature of 1010° C. for 1 hour ina muffle to form spheres having a R value of 0.69.

The calcined spheres were impregnated with Mo—Ni—P aqueous impregnationsolution by incipient wetness technique and then dried and calcined at510° C. to decompose the Mo—Ni—P impregnation solution compounds. Thefinished catalyst, identified as Catalyst B, had a nominal active metalcontent of 3 wt % Mo, 1 wt % Ni and 1 wt % P. Catalyst properties wereas identified in Table 1 below.

Example 3

Aqueous streams of aluminum sulfate (7% Al₂O₃) and titanium sulfate (9%TiO₂) were mixed in a 9:1 ratio to form an aluminum-titanium sulfatemixture. City water (210 gallons) was added to the strike tank andheated to 68° C. and the contents of the strike tank were maintained atthis temperature for the remainder of the process. Flows ofaluminum-titanium sulfate mixture and sodium aluminate were thenconcomitantly added to the strike tank. The sodium aluminate flow ratewas varied to maintain a constant pH of 7.6 in the strike tank. Thealuminum-titanium sulfate mixture flow was stopped 22 minutes after thestart of the simultaneous aluminum-titanium sulfate mixture and sodiumaluminate flows. Sodium aluminate flow was turned off when a pH of 9.2was obtained in the strike tank. The precipitated titania alumina mixwas then filtered and washed on a filter belt to remove residual sodiumand sulfate. The resulting filter cake was then spray dried. Driedtitania alumina powder was then used to make catalyst support.

The dried powder contains 3.5 wt. % TiO₂ (dry basis) and the balance(dry basis) is alumina (Al₂O₃). The powder contained 26% water. Thetitania alumina powder was peptized by mixing nitric acid/acetic acidand water to form a slurry containing 30% solids. The slurry was formedinto spheres on a dripping column. Wet spheres were dried at 120° C. andcalcined at a temperature of 1050° C. for 1 hour in a muffle to formspheres having a R value of 0.76.

The calcined spheres were impregnated with Mo—Ni—P aqueous impregnationsolution by incipient wetness technique and then dried and calcined at510° C. to decompose the Mo—Ni—P impregnation solution compounds. Thefinished catalyst, identified as Catalyst C, had a nominal active metalcontent of 3 wt % Mo, 1 wt % Ni and 1 wt % P. Catalyst properties wereas identified in Table 1 below.

Example 4

Aqueous streams of aluminum sulfate (7 wt % Al₂O₃) and titanium sulfate(9 wt % TiO₂) were mixed in a 9:1 ratio to form an aluminum-titaniumsulfate mixture. City water (270 gallons) was added to the strike tankand heated to 66° C. and the contents of the strike tank were maintainedat this temperature for the remainder of the process. Four gallons ofaluminum-titanium sulfate mixture was added to the strike tank. Flows ofaluminum-titanium sulfate mixture and sodium aluminate were thenconcomitantly added to the strike tank. The sodium aluminate flow ratewas varied to maintain a constant pH of 7.6 in the strike tank. Thealuminum-titanium sulfate mixture flow was stopped 22 minutes after thestart of the simultaneous aluminum-titanium sulfate mixture and sodiumaluminate flows. Sodium aluminate flow was turned off when a pH of 9.2was obtained in the strike tank. The precipitated titania alumina mixwas then filtered and washed on a filter belt to remove residual sodiumand sulfate. The resulting filter cake was then spray dried. Driedtitania alumina powder was then used to make catalyst support.

The dried powder contains 3.5 wt. % TiO2 (dry basis) and the balance(dry basis) is alumina (Al₂O₃). The powder contained 26% water. Thetitania alumina powder was peptized by mixing nitric acid/acetic acidand water to form a slurry containing 23% solids. The slurry was formedinto spheres on a dripping column. Wet spheres were dried at 120° C. andcalcined at a temperature of 1057° C. for 1 hour in a muffle to formspheres having a R value of 0.91.

The calcined spheres were impregnated with Mo—Ni—P aqueous impregnationsolution impregnation solution compounds. The finished catalyst,identified as Catalyst D, had a nominal active metal content of 3 wt %Mo, 1 wt % Ni and 1 wt % P. Catalyst properties were as identified inTable 1 below.

TABLE 1 Catalyst Properties of Catalysts A-D Catalyst A Catalyst BCatalyst C Catalyst D Titania Content, wt % 0 3.5 3.5 3.5 SA, m2/g 96103 94 102 PV, cm3/g 0.79 0.90 0.83 0.96 PSD, vol % <100 Å 0.6 0.0 0.00.0 100-200 Å 27.6 15.0 18.9 16.7 200-500 Å 32.5 48.9 39.5 36.7 >500 Å39.6 36.3 41.4 46.6 >1,000 Å 35.7 30.4 35.9 40.4

Example 5

Titania alumina spheres were prepared as described in Example 4 abovewith the exception that the dried spheres were calcined at a temperatureof 600° C. in order to obtain a mesopore structure with smaller porediameters. The R value of the calcined spheres was 0.15. The porestructure of Catalyst E was similar to the pore structure of a lowtemperature calcined desulfurization catalyst. Properties of Catalyst Eare shown in Table 2 below.

TABLE 2 Properties of Catalyst E Catalyst E SA, m2/g 231 PV, cm3/g 0.71PSD, vol % <50 Å 7.5 50-100 Å 68.3 100-200 Å 11.8 200-500 Å 6.8 >500 Å5.5

Example 6

Catalysts A, B, C, D and E were evaluated for performance in ahydrotreating process as described hereinafter. The catalyst pelletswere loaded in a plug-flow reactor. The feed consisted of an atmosphericresid and hydrogen. The resid had a metal content of 362 ppm V and 71ppm Ni and a Sulfur content of 4.6 wt %. The reactor temperature wasmaintained at different levels between 395-375° C., and the averagehourly space velocity was 0.8 L/(L·h). Comparative results for metal andsulfur conversion are given in Table 3 below. The results are given atthree different time-on-stream values (210, 402, and 738 hours) and thecorresponding reactor temperatures.

TABLE 3 Catalyst Testing Results Vanadium conversion, % Nickelconversion, % Sulfur conversion, % MCR conversion, % at 210 h, at 402 h,at 737 h, at 210 h, at 402 h, at 737 h, at 210 h, at 402 h, at 737 h, at210 h, at 402 h, at 737 h, 395° C. 390° C. 385° C. 395° C. 390° C. 385°C. 395° C. 390° C. 385° C. 395° C. 390° C. 385° C. Catalyst A 68.5 60.451.2 52.4 46.3 39.2 45.2 40.8 40.1 27.8 25.5 23.8 Catalyst B 71.2 63.253.1 55.8 49.4 41.0 58.8 52.3 41.1 35.9 32.0 26.2 Catalyst C 72.8 67.954.8 54.8 49.9 38.7 51.8 47.2 35.8 32.5 30.8 24.3 Catalyst D 74.6 67.558.8 57.9 52.2 45.8 48.7 43.0 37.1 33.6 30.5 26.8 Catalyst E 66.3 55.841.0 48.4 40.3 28.7 46.2 45.3 31.5 29.4 28.3 20.6

As shown in the Table 3 above, Catalysts B, C and D, being promoted withtitania and having a pore structure according to the present invention,exhibited enhanced performance for metal, sulfur and MCR conversion whencompared to the performance of Catalyst A (alumina only). While CatalystE exhibited an initial performance comparable to Catalyst A, theperformance of Catalyst E for conversion of metals, sulfur and MCRunexpectedly declined over time evidencing a lack of stability.

Reasonable variations, modifications and adaptations of the inventioncan be made within the scope of the described disclosure and theappended claims without departing from the scope of the invention.

The invention claimed is:
 1. A calcined spheroidal catalyst supportcomprising co-precipitated titania alumina having less than 5 wt %titania based on the total titania alumina, said support having a totalpore volume in the range of about 0.7 to about 1.2 cc/g, and a porevolume distribution such that greater than 40% of the total pore volumehave pores in a diameter larger than 200 Å, about 30% or greater of thetotal pore volume have pores in the range of about 200 Å to about 500 Åand, greater than 10% of the total pore volume have pores with adiameter above 1000 Å; wherein: (a) the co-precipitated titania aluminaresults from simultaneous co-precipitation of aqueous solutions ofaluminum sulfate, sodium aluminate and titanium sulfate; and (b) thecalcined support has been calcined at a temperature of about 960° C. toabout 1100° C.
 2. The support of claim 1 having a total pore volume inthe range of about 0.8 to about 1.1 cc/g.
 3. The support of claim 1wherein titania is present in the co-precipitated titania alumina in anamount ranging from about 2.5 to about 4.0 wt % titania, based on thetotal weight of the titania alumina.
 4. The support of claim 1 whereinthe support comprises at least 90wt % titania alumina having an aluminaR value of from about 0.4 to about 1.7, wherein R is the ratio betweenthe integrated intensity of the X-ray diffraction peak at 2Θ=32° and theintegrated intensity of the X-ray diffraction peak at 2Θ=46°.
 5. Thesupport of claim 1 wherein from about 50% to about 90% of the total porevolume is in pores having a diameter larger than 200 Å; from about 30%to about 80% of the total pore volume is in pores having a diameter fromabout 200 to about 500 Å; and greater than 15% of the total pore volumeof the support have pores in a diameter above 1000 Å.
 6. The support ofclaim 1 wherein from about 30% to about 80% of the total pore volume isin pores having a diameter from about 200 to about 500 Å.
 7. The supportof claim 1 wherein greater than 15% of the total pore volume of thesupport is in pores having a diameter above 1000 Å.
 8. A calcinedspheroidal catalyst support comprising co-precipitated titania aluminahaving less than 5 wt % titania based on the total titania alumina, saidsupport having a total pore volume in the range of about 0.7 to about1.2 cc/g, and a pore volume distribution such that greater than 40% ofthe total pore volume have pores in a diameter larger than 200 Å, about30% or greater of the total pore volume have pores in the range of about200 Å to about 500 Å and, greater than 30% of the total pore volume havepores with a diameter above 1000 Å.
 9. The support of claim 8 having atotal pore volume in the range of about 0.8 to about 1.1 cc/g.
 10. Thesupport of claim 8 wherein titania is present in the co-precipitatedtitania alumina in an amount ranging from about 2.5 to about 4.0 wt %titania, based on the total weight of the titania alumina.
 11. Thesupport of claim 8 wherein the support comprises at least 90 wt %titania alumina having an alumina R value of from about 0.4 to about1.7, wherein R is the ratio between the integrated intensity of theX-ray diffraction peak at 2Θ=32° and the integrated intensity of theX-ray diffraction peak at 2Θ=46°.
 12. The support of claim 8 whereinfrom about 50% to about 90% of the total pore volume is in pores havinga diameter larger than 200 Å; from about 30% to about 80% of the totalpore volume is in pores having a diameter from about 200 to about 500 Å;and greater than 15% of the total pore volume of the support have poresin a diameter above 1000 Å.
 13. The support of claim 8 wherein fromabout 30% to about 80% of the total pore volume is in pores having adiameter from about 200 to about 500 Å.
 14. The support of claim 8wherein greater than 15% of the total pore volume of the support is inpores having a diameter above 1000 Å.
 15. The support of claim 8 whereinthe support has been calcined at a temperature of about 960° C. to about1100° C.